validate.js require method doesn't work for attributes whose value is evaluated to false

[marianoguerra]

the line 22 of validate contains the following

if (!newDoc[field]) forbidden(message);

that means that if the field evalueates to false (like 0, 0.0, "" or false) then it will return forbidden

the line should be

if (typeof(newDoc[field]) === "undefined") forbidden(message);